T. Abu-Orabi, S.; Atfah, A.; A.S. Ali, A.; Abu-Shandi, K.; Al-Hamdany, R. Facile and Convenient Synthesis of Triazolopyridazine Derivatives via 1,3-Dipolar Cycloaddition Reaction of Organic Azides‡. ajc 2010, 11, 774-783.